[U-Boot] Sdcard boot for a generic allwinner q8 clone A33 tablet not work.

Hi, i'm trying to boot a classic A33 q8 clone with uboot copied in sdcard but nothing happen (not backlight on)

dd if=u-boot-sunxi-with-spl.bin of=/dev/sdb bs=1024 seek=8 on the partitioned sdcard for reference

if i compile with configuration for A13 based tablet on A13 based tablet it work like charm, so i suppose i'm not in wrong in my setup, how can i debug ?

I dont have sd/usart adapter so i cannot boot from fel, there is a way to make blink backlight to understand if it is working and is an lcd problem ?

On original android it work perfectly.

I attach original fex and .configure for your references.

Thank